Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sekine, Megumi; Matsuki, Takuya; Suzuki, Satoshi*; Tsutagi, Koichi; Nishida, Naoki; Kitao, Takahiko; Tomikawa, Hirofumi; Nakamura, Hironobu; LaFleur, A.*; Browne, M.*
JAEA-Technology 2019-023, 160 Pages, 2020/03
The International Atomic Energy Agency (IAEA) has proposed in its Research and Development plan (STR-385), the development of technology to enable real-time flow measurement of nuclear material as a part of an advanced approach to effective and efficient safeguards for reprocessing facilities. To address this, Japan Atomic Energy Agency (JAEA) has been tackling development of a new detector to enable monitoring of Pu in solutions with numerous FPs as a joint research program with U.S. DOE to cover whole reprocessing process. In this study, High Active Liquid Waste (HALW) Storage Facility in Tokai Reprocessing Plant was used as the test field. At first, the design information of HALW storage tank and radiation (type and intensity) were investigated to develop a Monte Carlo N-Particle Transport Code (MCNP) model. And then, dose rate distribution outside/ inside of the concrete cell where the HALW tank is located was measured to design new detectors and check MCNP model applicability. Using the newly designed detectors, gamma rays and neutron were continuously measured at the outside/ inside of the concrete cell to assess the radiation characteristics and to optimize detector position. Finally, the applicability for Pu monitoring technology was evaluated based on the simulation results and gamma-ray/neutron measurement results. We have found that there is possibility to monitor the change of Pu amount in solution by combination both of gamma-ray and neutron measurement. The results of this study suggested the applicability and capability of the Pu motoring to enhance safeguards for entire reprocessing facility which handles Pu with FP as a feasibility study. This is final report of this project.
Quinay, P. E. B.; Ichimura, Tsuyoshi*; Hori, Muneo*; Wijerathne, M. L. L.*; Nishida, Akemi
Progress in Nuclear Science and Technology (Internet), 2, p.516 - 523, 2011/10
In this paper, we conducted a numerical analysis based on a fault-structure system. We developed a full three dimensional model that includes from a fault to structures at the surface. However, huge computational cost is required to solve these components simultaneously. Ichimura and Hori (2009a) presented a macro-micro analysis method based on singular perturbation expansion to reduce computational cost. We implemented a highly tuned finite-element code for macro-micro analysis systems to handle large-scale wave propagation in a complicated crust structure as well as the seismic response of a structure at the surface. After verifying the accuracy by comparing the results with analytical Green's function solutions, we demonstrate a seismic response using a model of a nuclear power plant structure. Our methodology can enable detailed prediction of the seismic response of a nuclear facility, permitting the generation of more reliable estimates of the seismic safety of nuclear facilities.
Bakhtiari, M.; Tamai, Hiroshi; Kawano, Yasunori; Kramer, G. J.*; Isayama, Akihiko; Nakano, Tomohide; Kamiya, Kensaku; Yoshino, Ryuji; Miura, Yukitoshi; Kusama, Yoshinori; et al.
Nuclear Fusion, 45(5), p.318 - 325, 2005/05
Times Cited Count:45 Percentile:79.15(Physics, Fluids & Plasmas)In the previous works we had shown that injecting a mixture of large amounts of hydrogen and small amounts of argon can terminate a tokamak discharge quickly with avoiding runaway electron generation. In this work we have done the same experiments but with different gases in addition to argon. In fact we compared the effect of the puffing of argon, krypton, and xenon gases with and without simultaneous hydrogen gas puffing on disruption mitigation. We observed that injecting all impurities in the form of an admixture in hydrogen lead to faster plasma shutdowns with less runaway electron generation. We also found that injecting krypton gas (with or without hydrogen) seems to be a good candidate for plasma shutdown purposes since it induces low heat flux to divertor plates and avoids runaway electron generation more effectively.
Bakhtiari, M.; Kawano, Yasunori; Tamai, Hiroshi; Miura, Yushi; Yoshino, Ryuji; Nishida, Yasushi*
Nuclear Fusion, 42(10), p.1197 - 1204, 2002/10
Times Cited Count:49 Percentile:80.52(Physics, Fluids & Plasmas)no abstracts in English
Bakhtiari, M.; Yoshino, Ryuji; Nishida, Yasushi*
Fusion Science and Technology, 41(2), p.77 - 87, 2002/03
Times Cited Count:6 Percentile:39.48(Nuclear Science & Technology)no abstracts in English
Saito, J.*; Suda, Takanori*; Yamashita, Shinichiro*; Onuki, Somei*; Takahashi, Heishichiro*; Akasaka, Naoaki; Nishida, M.; Ukai, Shigeharu
Journal of Nuclear Materials, 258-263(Part 2), p.1264 - 1268, 1998/10
Times Cited Count:40 Percentile:92.81(Materials Science, Multidisciplinary)None
; Harada, Makoto; Okada, H.; ; ; Shikakura, Sakae; Asabe, K.*; Nishida, T.*; Fujiwara, M.*
Journal of Nuclear Materials, 204, p.65 - 73, 1993/00
Times Cited Count:276 Percentile:99.9(Materials Science, Multidisciplinary)None